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/* Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
/* Tiny charger configuration */
#include "common.h"
#include "debug.h"
#include "irq_handler.h"
#include "registers.h"
#include "sha1.h"
#include "usb_pd.h"
#include "util.h"
extern void pd_rx_handler(void);
/* RW firmware reset vector */
static uint32_t * const rw_rst =
(uint32_t *)(CONFIG_FLASH_BASE+CONFIG_FW_RW_OFF+4);
/* External interrupt EXTINT7 for external comparator on PA7 */
void IRQ_HANDLER(STM32_IRQ_EXTI4_15)(void)
{
/* clear the interrupt */
STM32_EXTI_PR = STM32_EXTI_PR;
/* trigger reception handling */
pd_rx_handler();
}
static void jump_to_rw(void)
{
void (*jump_rw_rst)(void) = (void *)*rw_rst;
debug_printf("Jump to RW\n");
/* Disable interrupts */
asm volatile("cpsid i");
/* Call RW firmware reset vector */
jump_rw_rst();
}
int is_ro_mode(void)
{
return (uint32_t)&jump_to_rw < (uint32_t)rw_rst;
}
static int check_rw_valid(void)
{
uint32_t *hash;
uint32_t *fw_hash = (uint32_t *)
(CONFIG_FLASH_BASE + CONFIG_FLASH_SIZE - 32);
/* Check if we have a RW firmware flashed */
if (*rw_rst == 0xffffffff)
return 0;
hash = (uint32_t *)flash_hash_rw();
/* TODO(crosbug.com/p/28336) use secret key to check RW */
if (memcmp(hash, fw_hash, SHA1_DIGEST_SIZE) != 0) {
/* Firmware doesn't match the recorded hash */
debug_printf("SHA-1 %08x %08x %08x %08x %08x\n",
hash[0], hash[1], hash[2], hash[3], hash[4]);
debug_printf("FW SHA-1 %08x %08x %08x %08x %08x\n",
fw_hash[0], fw_hash[1], fw_hash[2],
fw_hash[3], fw_hash[4]);
return 0;
}
return 1;
}
extern void pd_task(void);
int main(void)
{
hardware_init();
debug_printf("Power supply started ... %s\n",
is_ro_mode() ? "RO" : "RW");
/* Verify RW firmware and use it if valid */
if (is_ro_mode() && check_rw_valid())
jump_to_rw();
/* background loop for PD events */
pd_task();
debug_printf("background loop exited !\n");
/* we should never reach that point */
cpu_reset();
return 0;
}
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